Electrical busbar with alignment features

ABSTRACT

A busbar system is configured to carry current, such as, for example, in a battery system. The busbar system includes two or more busbars, that interface at respective surfaces and are aligned by one or more alignment features. The one or more alignment features may include a boss feature such as a pin or other protrusion, a recess such as a hole, slot, or other recess feature, or both a boss feature and a recess feature. Each busbar may include an alignment feature that engages with the alignment feature of the other busbar to cause, maintain, or otherwise effect alignment. Alignment of the busbars ensures relative position, prevents relative motion, or both. The busbars are engaged with each other by positioning the busbars such that their mating surfaces can engage, and then engaging alignment features of the busbars to provide alignment of the busbars relative to each other.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 62/760,869 filed Nov. 13, 2018, the disclosure of whichis hereby incorporated by reference herein in its entirety.

The present disclosure is directed towards an electrical busbar forconducting current, and more particularly towards an electrical busbarhaving alignment features.

INTRODUCTION

Electrical busbars are used to provide a path for current amongcomponents. For example, battery systems use busbars to connect cells inparallel and/or series, couple cells to components such as switches,connectors, or fuses. Two or more busbars can be connected together tofurther extend the current path. It would be advantageous to provide foralignment of busbars to prevent a change in relative position, relativeorientation, or both.

Busbar alignment can be achieved with an assembly aid (e.g., a jig) thatconstrains one or both of the busbars so they cannot move relatively toeach other while being secured. However, the additional cost and mass(e.g., if it is a permanent part of the assembly) might not beacceptable.

SUMMARY

The present disclosure is direct to a busbar system. The busbar systemincludes a first busbar and a second busbar. The first busbar includes afirst surface and at least one boss feature extending from the firstsurface. The second busbar includes a second surface that is configuredto contact the first surface and at least one recess feature in thesecond surface. The at least one boss feature is configured to engagewith the at least one recess feature to limit motion of the first busbarrelative to the second busbar. For example, each of the first busbar andthe second busbar are configured to carry electrical current and allowelectrical current to flow from either busbar to the other busbar.

In some embodiments, the at least one boss feature includes a pin. Forexample, in some embodiments, the pin includes a cylindrical pin, a pinhaving a circular cross section, a pin having a diamond-shaped crosssection, a pin having any other suitable cross section, or anycombination thereof. In some embodiments, the at least one boss featureincludes a friction drilled feature. In some embodiments, the at leastone boss feature includes a pressed feature.

In some embodiments, the at least one recess feature includes a hole.For example, in some embodiments, the at least one recess featureincludes a circular hole, a non-circular hole, any other suitably shapedhole, or any combination thereof. In some embodiments, the at least onerecess feature includes a slot. For example, in some embodiments, the atleast one recess feature includes a rectangular slot, a slot withrounded ends, a curved slot, any other suitably shaped slot, or anycombination thereof. In some embodiments, the at least one recessfeature includes a punched feature, a pressed feature, or both.

In some embodiments, the first busbar includes a first through-hole, thesecond busbar further includes a second through-hole, and when the atleast one boss feature is engaged with the at least one recess feature,the first through-hole is aligned with the second through-hole. Forexample, in some embodiments, a fastener is configured to extend thoughthe aligned first through-hole and second through-hole and apply aclamping force to press the first busbar and the second busbar together.

In some embodiments, the at least one boss feature includes more thanone boss feature. For example, in some embodiments, the at least oneboss feature includes two boss features. In a further example, the twoboss features may have substantially the same shape. In a furtherexample, the two boss features may have substantially different shapes.In some embodiments, the at least one recess feature includes more thanone recess feature. For example, in some embodiments, the at least onerecess feature includes two recess features. In a further example, thetwo recess features may have substantially the same shape. In a furtherexample, the two recess features may have substantially differentshapes.

In some embodiments, the first busbar includes at least one secondrecess feature in the first surface, the second busbar includes at leastone second boss feature in the second surface, and the at least onesecond boss feature is configured to engage with the at least one secondrecess feature to prevent motion of the first busbar relative to thesecond busbar.

In some embodiments, the present disclosure is directed to a method forassembling a busbar system. The method includes positioning a firstbusbar and a second busbar. The first busbar includes a first surfaceand at least one boss feature on the first surface. The second busbarincludes a second surface and at least one recess feature on the secondsurface. The method also includes engaging the at least one boss featurewith the at least one recess feature to prevent relative motion of thefirst busbar and the second busbar. In some embodiments, the methodincludes pressing the first busbar and the second busbar together sothat the first surface and the second surface are in contact with eachother.

In some embodiments, the first surface and the second surface are incontact with each other at an interface, and the method includesaffixing the first busbar to the second busbar. Affixing is achieved bywelding the interface, brazing the interface, soldering the interface,pressing the interface, fastening the interface, crimping the interface,deforming the interface, or a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure, in accordance with one or more variousembodiments, is described in detail with reference to the followingfigures. The drawings are provided for purposes of illustration only andmerely depict typical or example embodiments. These drawings areprovided to facilitate an understanding of the concepts disclosed hereinand shall not be considered limiting of the breadth, scope, orapplicability of these concepts. It should be noted that for clarity andease of illustration these drawings are not necessarily made to scale.

FIG. 1 shows two configurations of an illustrative busbar system, inaccordance with some embodiments of the present disclosure;

FIG. 2 shows a perspective view of a first busbar and a second busbar ofan illustrative battery system, in accordance with some embodiments ofthe present disclosure;

FIG. 3A shows a perspective view of a first busbar, having alignmentfeatures, in accordance with some embodiments of the present disclosure

FIG. 3B shows a perspective view of a busbar, having recess alignmentfeatures, in accordance with some embodiments of the present disclosure;

FIG. 4 shows a perspective view of two busbars, having the samealignment features, in accordance with some embodiments of the presentdisclosure;

FIG. 5 shows perspective views of portions of busbars havingillustrative boss features, in accordance with some embodiments of thepresent disclosure;

FIG. 6 shows perspective views of portions of busbars havingillustrative recess features, in accordance with some embodiments of thepresent disclosure; and

FIG. 7 shows a flowchart of an illustrative process for forming a busbarassembly, in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION

FIG. 1 shows two configurations 100 and 150 of an illustrative busbarsystem, in accordance with some embodiments of the present disclosure.The busbar system includes busbar 101 and busbar 102, which are eachconfigured to engage with a respectively plurality of battery cells andprovide a conduit for current. The respective pluralities of batterycells may be arranged spatially, and each of busbar 101 and busbar 102may include features that engage with each respective battery cell toprovide electrical contact. For example, busbar 101 and busbar 102 mayeach provide a path for current to flow in parallel from the respectiveplurality of battery cells. Busbar 101 and busbar 102 are electricallycoupled together. For example, as illustrated, busbar 101 and busbar 102are fastened together. Alignment features 103 of busbar 101 andalignment features 104 of busbar 102 help maintain alignment duringarrangement of busbars 101 and 102, during fastening of busbars 101 and102 together, during fastening of busbars 101 and 102 to the respectiveplurality of battery cells, during operation (e.g., in an electricvehicle that undergoes acceleration), or any combination thereof.Alignment features 103 and 104 may include any suitable recess features,boss features, or both, that constrain at least some motion ordisplacement of busbars 101 and 102 relative to each other. Asillustrated, alignment features 103 and 104 include tapered recessfeatures (e.g., tapered blind holes) and tapered boss features (e.g.,tapered pins), respectively.

As illustrated, busbars 101 and 102 are electrically coupled torespective pluralities of batteries 111 and 112. In configuration 100,busbar 101 and busbar 102 are not electrically coupled, whichcorresponds to, for example, a configuration during assembly, duringalignment, during manufacture, or any other time when busbar 101 andbusbar 102 need not be aligned, fastened, electrically coupled, or acombination thereof. In configuration 150, busbar 101 and busbar 102 areelectrically coupled, which corresponds to, for example, a configurationduring operation, during testing, or any other time when busbar 101 andbusbar 102 need be aligned, fastened, electrically coupled, or acombination thereof. For example, configuration 150 may include one ormore fasteners that affix busbars 101 and 102 to each other (e.g.,bolts, screws, threaded nuts, lock nuts, crimpable features, press-fitfeatures)

The present disclosure is directed to busbars having one or morealignment features (or “features”) that engage for alignment. In someembodiments, alignment features include boss features that extend from asurface and are continuous with the bulk busbar (e.g., formed from abusbar blank and accordingly of the same material). One or more featuresmay be included to constrain relative motion between the coupledbusbars. For example, engaging features of a first and second busbar mayinclude a boss feature and a recess feature. In a further example,because the boss feature is made of the base material, there will not bean interruption in current flow when the coupled busbars are in use.Busbars are made of electrically conducting material such as, forexample, copper, aluminum, any other suitable metal, alloy, or materialthat has a desired electrical conductivity, or any combination thereof.

In some embodiments, the alignment features provide alignment to aid thejoining of busbars. For example, the alignment features may keep thebusbars secured during fastening, welding (e.g., laser welding,ultrasonic welding), soldering, brazing, pressing, any other suitablejoining techniques, or any combination thereof.

In an illustrative example, a first busbar may include a pin and asecond busbar may include a blind hole. The pin may be sized for apress-fit operation with the hole such that no other parts (e.g.,fasteners) are required. In a further example, a busbar may includeseveral pins, or other suitable boss features, configured to engage withcorresponding recess features. Boss features may include, for example,pins (e.g., round pins, diamond pins, oval pins, triangular pins, or anyother suitable pin type), hemispherical bumps, ridges, tabs, anextension having any suitable uniform cross-section, an extension havingany suitable non-uniform cross-section (e.g., a cone, a pyramid), anyother suitable feature extending from a busbar surface, or anycombination thereof. Recess features may include, for example, holes(e.g., round holes), hemispherical indentations, slots, grooves, arecess having any suitable uniform cross-section, a recess having anysuitable non-uniform cross-section, any other suitable relief in abusbar surface, or any combination thereof.

A boss feature is configured to engage with one or more recess features(e.g., a round pin is configured to engage with a round hole or a slot).A recess feature is configured to engage with one or more boss features(e.g., a round hole may accommodate a round pin or a diamond pin). Insome embodiments, a busbar may include more than one alignment feature.For example, a first busbar may include two boss features configured toengage with two respective recess features of a second busbar. In afurther example, a busbar may include a boss feature and a recessfeature configured to engage with a respective second recess feature anda second boss feature of a second busbar. In a further example, a busbarmay include two boss features that are the same as each other (e.g., tworound pins of similar size, or two tabs of similar size and shape) orare different from each other (e.g., a round pin and a diamond pin, orround pins of differing sizes). In a further example, a busbar mayinclude two recess features that are the same as each other (e.g., tworound holes of similar diameter, or two slots of similar size) or aredifferent from each other (e.g., a round hole and a slot, or round holesof differing sizes).

An alignment feature may be formed in a busbar using any suitabletechnique, process, and equipment. For example, a boss feature such as apin may be formed in a busbar by friction drilling from one side with amold of the desired pin on the other side. In some such examples, thedrill bit need not pierce the busbar material completely, but rather mayheat up the material locally and push it into the mold to form the pin.In a further example, a busbar may be stamped, pressed, machined, orotherwise processed to form a boss feature. A recess feature may beformed by drilling, machining, punching, pressing, melting, any othersuitable process for forming a recess (e.g., by removing material orcausing material to flow), or any combination thereof.

The use of alignment features allows busbars to be accurately aligned,which may improve manufacturing quality, creepage/clearance safety,and/or structural rigidity. In some embodiments, because the alignmentfeatures do not include a different material than the busbar material,the joint may be less susceptible to corrosion, increased localelectrical resistance (e.g., interfacial resistance), and stress due todifferent coefficients of thermal expansion of different materials. Forexample, a pin-like alignment feature made from the base material of thebusbar helps eliminate these issues.

In some embodiments, alignment features allow for tighter tolerancesthan fasteners alone. In some embodiments, alignment features preventrelative motion of busbars coupled by a fastener (e.g., relative motioncaused by applied torque, normal forces, and/or friction forces actingon the bus bars during fastening).

In some embodiments, a busbar may include a particular boss feature orrecess feature that is configured to engage only some other alignmentfeatures of other busbars. For example, there may be several types ofbusbars, and only some combinations may be coupled together. In anillustrative example, boss features for larger current capacity busbarsmay be arranged (e.g., located) differently based on current capacity,to prevent mismatched busbars. In some embodiments, alignment featuresmay be keyed or otherwise shaped to only engage with a subset of otheralignment features. For example, for a plurality of busbar types, onlycertain types may be coupled together, based on the engagement of thecorresponding alignment features. In some embodiments, a recess featuremay be configured to engage with two or more boss features. For example,a first busbar may include two pins configured to engage in a singleslot of a second busbar to prevent relative motion of busbars.

FIG. 2 shows a perspective view of first busbar 201 and second busbar202 of illustrative battery system 200, in accordance with someembodiments of the present disclosure. First and second busbars 201 and202 are configured to be fastened together to provide a current-carryingpath. As illustrated, second busbar 202 is electrically coupled toelectrical terminal 203, which may include, for example, a DC busconnector, one or more electrical terminals, any other suitableelectrical termination, or any combination thereof. As illustrated,first busbar 201 is electrically coupled to contactor 205 (e.g.,fastened to contactor 205 as illustrated).

FIG. 3A shows a perspective view of busbar 300, having alignmentfeatures, in accordance with some embodiments of the present disclosure.The busbar 300 includes two pins 303 of round cross-section (i.e., roundpins). Accordingly, busbar 300 may be engaged with another busbar (e.g.,busbar 350 of FIG. 3B or any other suitable busbar) by inserting twopins 303 into corresponding holes of the other busbar.

FIG. 3B shows a perspective view of busbar 350, in accordance with someembodiments of the present disclosure. Busbar 350 includes recessfeatures 353. Recess features 353, as illustrated, includes circularholes. For example, alignment features 353 of busbar 350 may beconfigured to engage with alignment features 303 of busbar 300 of FIG.3A. Although busbars 300 and 350 shown in FIGS. 3A-3B include alignmentfeatures of circular cross-section (e.g., two round pins), busbars mayinclude any suitable number of boss features, each having any suitableshape and size, in accordance with some embodiments of the presentdisclosure.

FIG. 4 shows a perspective view of two busbars 400 and 402, having thesame alignment features, in accordance with some embodiments of thepresent disclosure. Busbars 400 and 402 each include a pin of roundcross-section (i.e., a round pin) and a recess feature (e.g., a circularhole as illustrated). In some embodiments, busbars 400 and 400 areidentical parts. This enables a single part to be used twice to make aconnection. As illustrated, a through-hole is centered between the pinand recess features of busbars 400 and 402, which causes thethrough-holes to be aligned when the pin and recess features of thebusbars are engaged. A fastener can then be inserted into the alignedthrough-holes. The pin and recess features are aligned 45 degreesrelative to the longitudinal axis of the busbars. Such an alignmentcauses the busbars to be aligned at 90 degrees when engaged. Thisalignment is merely illustrative and any suitable angle of alignment maybe used to achieve a desire alignment between the busbars.

In an illustrative example, busbars 300 and 350 of FIGS. 3A-3B may beconfigured to be fastened together to provide a current-carrying path(e.g., after alignment by engaging alignment features). In anotherillustrative example, busbars 400 and 402 of FIG. 4 may be configured tobe fastened together to provide a current-carrying path (e.g., afteralignment by engaging alignment features). When the pins are engagedwith the respective holes, the application of torque to a fastener isprevented from rotating either of the busbars relative to each other. Insome circumstances, engagement of the pins and holes maintains alignmentduring fastening, welding (e.g., laser welding, ultrasonic welding),soldering, brazing, pressing, crimping, any other suitable joiningtechniques, or any combination thereof.

FIG. 5 shows perspective views of portions of busbars havingillustrative boss features, in accordance with some embodiments of thepresent disclosure. Panel A shows a cylindrical pin (e.g., formed byfriction drilling or pressing the underside of the busbar with acylindrical mold on the top side). Panel B shows a conical pin (e.g.,formed by friction drilling or pressing the underside of the busbar witha conical mold on the top side). Panel C shows a hemispherical bump(e.g., formed by friction drilling or pressing the underside of thebusbar with a hemispherical mold on the top side or no mold). Panel Dshows a bent tab (e.g., formed by punching a three sided through-traceoutlining a tab and then bending the tab down). Panel E shows a diamondpin (e.g., formed by pressing the underside of the busbar with a diamondmold on the top side).

FIG. 6 shows perspective views of portions of busbars havingillustrative recess features, in accordance with some embodiments of thepresent disclosure. Panel A shows a cylindrical through hole (e.g.,formed by milling, laser cutting, water-jet cutting, plasma cutting,drilling or punching the busbar with a die from either side). Panel Bshows a through slot (e.g., formed by milling, laser cutting, water-jetcutting, plasma cutting, or punching). Panel C shows a hemisphericalindentation (e.g., formed by friction drilling or pressing the top sideof the busbar). Panel D shows a notch (e.g., formed by milling, lasercutting, water-jet cutting, plasma cutting, or punching). Panel E showsa non-circular hole (e.g., formed by milling, laser cutting, water-jetcutting, plasma cutting, or punching), which may be, but need not be,polygonal. The boss features illustrated in FIG. 5, and any othersuitable boss features, may be configured (e.g., located, sized, andshaped suitably) to engage with the recess features illustrated in FIG.5, or any other suitable recess features. For example, any or all of thepin of FIG. 5, panel A, the conical pin of FIG. 5, panel B, the bump ofFIG. 5, panel C, the bent tab of FIG. 5, panel D, and the boss featureof FIG. 5, panel E, may be configured to engage with a hole (e.g., shownin FIG. 6, panel A), a slot (e.g., shown in FIG. 6, panel B), anindentation (e.g., shown in FIG. 6, panel C), a notch (e.g., shown inFIG. 6, panel D), a pin having polygonal cross-section (e.g., shown inFIG. 6, panel E) any other suitable recess feature. For example, othersuitable recess features may include tapered holes, punched holes (e.g.,of any cross-sectional shape), any other through features, or anycombination thereof.

In an illustrative example, the busbars having align features of thepresent disclosure may be included as part of a battery system. Forexample, busbars may be included in battery systems, and may beconfigured to carry over an amp of current, over ten amps, or even overa hundred amps of current. In a further example, the busbars of thepresent disclosure may be included in relative high-voltage systems suchas system operating at over 100V, over 200V, over 400V, or at a greatervoltage. To illustrate, the battery system may be included in anelectric vehicle (e.g., may provide a DC bus to power electric motors ofthe vehicle). In some embodiments, a busbar may include a relativelysimple geometric shape (e.g., a bar, a polygon, an “L” or “U” shape). Insome embodiments, a busbar may include a relatively complex shape (e.g.,comb-shaped, compound bends, multiple bends, bends in more than oneplane, a plurality of connection points). In some embodiments, a busbarmay be structurally rigid, having a cross-sectional area sufficient tocarry an expected current load (e.g., which may be over ten amps, orover one hundred amps). For example, a busbar may be hundreds of micronsthick, a millimeter thick, several millimeters thick, or even acentimeter thick (e.g., depending on the width to achieve a desiredcross-sectional area). The alignment features of the present disclosuremay be, but need not be, sized based on dimensions of the busbar.

FIG. 7 shows a flowchart of illustrative process 700 for forming abusbar assembly, in accordance with some embodiments of the presentdisclosure.

Step 702 includes positioning a first busbar. The first busbar has afirst surface and at least one boss feature on the first surface. Forexample, any of the boss features of FIG. 5, any other suitable bossfeatures, or any combination of boss features thereof, may be arrangedon the surface. Positioning the first busbar may include setting aposition (e.g., in three-dimensional space, or on a two-dimensionalplane such as a work surface), an orientation, or both, relative to anysuitable reference such as, for example, a tool, a work surface, ameasurement device, a point in space, another busbar (e.g., the secondbusbar of step 704), or any other suitable reference or combination ofreferences.

Step 704 includes positioning a second busbar. The second busbar has asecond surface and at least one recess feature on the second surface.For example, any of the recess features of FIG. 6, any other suitablerecess features, or any combination of recess features thereof, may bearranged on the surface. Positioning the second busbar may includesetting a position (e.g., in three-dimensional space, or on atwo-dimensional plane such as a work surface), an orientation, or both,relative to any suitable reference such as, for example, a tool, a worksurface, a measurement device, a point in space, the first busbar, orany other suitable reference or combination of references. Steps 702 and704 may be performed in any suitable order. For example, steps 702 and704 may be performed simultaneously, or sequentially (e.g., with eitherstep performed first).

Step 706 includes engaging the at least one boss feature with the atleast one recess feature to prevent relative motion of the first busbarand the second busbar. The engagement may constrain one, more than one,or all degrees of freedom of the first and second busbars relative toeach other. For example, engagement of the at least one boss feature andthe at least one recess feature may prevent relative rotation andrelative translation in a plane. In some embodiments, a friction weld orpress machine is used to make at least one of the boss feature on thefirst busbar and the recess feature on the second busbar. In someembodiments, the same friction weld or press machine (e.g., the machineused to make the boss feature on the first busbar) is used to positionthe first busbar in step 702 or the second busbar in step 704 and assistin engaging the boss feature with the recess feature in step 706. Insome embodiments, the same friction weld or press machine is used toposition the first and second busbars in steps 702 and 704 and engagethe boss feature with the recess feature in step 706. For example, thefriction weld or press machine may include two movable grippers toposition the busbars and engage the corresponding features. This can beachieved by programming or reprogramming the machine to perform multiplefunctions, which can decrease manufacturing costs.

In some embodiments, when the first and second busbars are aligned(e.g., alignment features are engaged with each other), they may beaffixed to maintain their spatial configuration. For example, affixingmay include fastening, welding, brazing, adhering, pressing, crimping,any other suitable technique for affixing first and second busbars, orany combination thereof. The affixing may be, but need not be,reversible (e.g., while fastening may be reversible, welding might notbe reversible).

The foregoing is merely illustrative of the principles of thisdisclosure, and various modifications may be made by those skilled inthe art without departing from the scope of this disclosure. The abovedescribed embodiments are presented for purposes of illustration and notof limitation. The present disclosure also can take many forms otherthan those explicitly described herein. Accordingly, it is emphasizedthat this disclosure is not limited to the explicitly disclosed methods,systems, and apparatuses, but is intended to include variations to andmodifications thereof, which are within the spirit of the followingclaims.

What is claimed is:
 1. A busbar system comprising: a first busbarcomprising: a first surface; and at least one boss feature extendingfrom the first surface; and a second busbar comprising: a second surfacethat is configured to contact the first surface; and at least one recessfeature in the second surface, wherein: the at least one boss feature isconfigured to engage with the at least one recess feature to limitmotion of the first busbar relative to the second busbar.
 2. The busbarsystem of claim 1, wherein the at least one boss feature comprises apin.
 3. The busbar system of claim 1, wherein the at least one bossfeature comprises a friction drilled feature.
 4. The busbar system ofclaim 1, wherein the at least one boss feature comprises a pressedfeature.
 5. The busbar system of claim 1, wherein the at least onerecess feature comprises a hole.
 6. The busbar system of claim 1,wherein the at least one recess feature comprises a slot.
 7. The busbarsystem of claim 1, wherein the at least one recess feature comprises atleast one of a punched feature and a pressed feature.
 8. The busbarsystem of claim 1, wherein the first busbar and the second busbar areconfigured to carry electrical current.
 9. The busbar system of claim 1,wherein: the first busbar further comprises a first through-hole; thesecond busbar further comprises a second through-hole; and when the atleast one boss feature is engaged with the at least one recess feature,the first through-hole is aligned with the second through-hole.
 10. Thebusbar system of claim 9, further comprising a fastener configured to:extend though the aligned first through-hole and second through-hole;and apply a clamping force to press the first busbar and the secondbusbar together.
 11. The busbar system of claim 1, wherein the at leastone boss feature comprises two boss features.
 12. The busbar system ofclaim 11, wherein the two boss features have substantially the sameshape.
 13. The busbar system of claim 11, wherein the two boss featureshave different shapes.
 14. The busbar system of claim 1, wherein the atleast one recess feature comprises two recess features.
 15. The busbarsystem of claim 14, wherein the two recess features have substantiallythe same shape.
 16. The busbar system of claim 14, wherein the tworecess features have different shapes.
 17. The busbar system of claim 1,wherein: the first busbar further comprises at least one second recessfeature in the first surface; the second busbar further comprises atleast one second boss feature in the second surface; and the at leastone second boss feature is configured to engage with the at least onesecond recess feature to prevent motion of the first busbar relative tothe second busbar.
 18. A method for assembling a busbar system, themethod comprising: positioning a first busbar comprising a first surfaceand at least one boss feature on the first surface; positioning a secondbusbar comprising a second surface and at least one recess feature onthe second surface; and engaging the at least one boss feature with theat least one recess feature to prevent relative motion of the firstbusbar and the second busbar.
 19. The method of claim 18, furthercomprising pressing the first busbar and the second busbar together sothat the first surface and the second surface are in contact with eachother.
 20. The method of claim 18, wherein the first surface and thesecond surface are in contact with each other at an interface, themethod further comprising affixing the first busbar to the second busbarby at least one of welding the interface, brazing the interface,soldering the interface, pressing the interface, fastening theinterface, crimping the interface, and deforming the interface.